pcappick: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/pcappick - from package: pcaputils

You may install the required package with command apt-get install {package}

Error in other languages:
pcappick: bevel nie gevind nie
pcappick: comandă negăsită
pcappick: comando não encontrado
pcappick: commande introuvable
pcappick: command not found
pcappick: käsku ei ole
pcappick: không tìm thấy lệnh
pcappick: komanda nerasta
pcappick: Kommando nicht gefunden.
pcappick: kommandot finns inte
pcappick: komut yok
pcappick: nie znaleziono polecenia
pcappick: níor aimsíodh an t-ordú
pcappick: no se encontró la orden
pcappick: no s'ha trobat l'ordre
pcappick: opdracht niet gevonden
pcappick: parancs nem található
pcappick: perintah tidak ditemukan
pcappick: príkaz nenájdený
pcappick: příkaz nenalezen
pcappick: команда не найдена
pcappick: командата не е открита
pcappick: 命令找不到
pcappick: コマンドが見つかりません